Abuse Of Mom In Childhood And Autism Risk

The latest in the litany of “this is linked to autism” findings is abuse of the mother in childhood. Researchers publishing in JAMA Psychiatry report that women who experienced the “highest level” of abuse when they were girls had about three times the risk of non-abused women of having an autistic child. In the current work, based on data collected in the course of the large Nurses’ Health Study II, the authors looked at data for 54,963 women who reported in 2005 whether or not they had a child with autism. The women also completed a 2001 questionnaire about their experiences with childhood abuse. Of this group, 451 were the biological parent of an autistic child.

The authors offer four possible explanations for the mathematical link they identified between maternal childhood abuse and having an autistic child. The first is that they left out some other important factors, such as infection or poor diet. The second, to which they devote the most words, is that imbalances of various interacting stress-related pathways, including inflammation, somehow led to autism in an abused woman’s child. Their third possibility still ties in inflammation, but this time, epigenetic factors–influences on the mother’s gene expression–would be to blame. Finally, they posit that childhood abuse often comes from mentally ill family members and suggest that a genetic link between mental illness and autism might explain the findings.

The one genetic possibility they left out is that the women themselves might have been autistic but undiagnosed or have shown traits of autism without meeting the threshold definition of it. Unless their manifestation of autism is quite intense, girls and women often go undiagnosed or are diagnosed with personality or other disorders. In addition, because of some of the key behaviors associated with autism, autistic children are more likely–much more likely [PDF]–than non-autistic children to be abused, physically, emotionally, and sexually. A girl showing even some of those traits, or a “broad autism phenotype,” is not excluded from being a target just because she never had an autism diagnosis. Appearing unresponsive to discipline, “overly” sensitive to inputs from the world around them, unable to read nonverbal communication, including building anger or threat or bullying — all of these can and do translate into abuse from family members, caregivers, peers, and others and leave a girl like this vulnerable.

A review of one of the questionnaires the study uses (the 2005 version [PDF]) turned up no questions pertaining to autism traits in the mother or questions asking about having an autistic child. Indeed, a very small number of questions relate to behavioral or mental health, primarily phobias and anxiety, and almost none to neurological health; a version from another year seemed to focus on depression. I wonder what the researchers would uncover if they asked these mothers, for example, about their social experiences in childhood, their sensory experiences, their response to stimuli, and other questions relevant to autism. These kinds of queries would be one way to tease out whether or not autism or autism-related traits in the mother were another contributing factor not only to autism in the child but also to maternal childhood abuse.

What would the relevance of autism traits in the mother be? Genetics investigations suggest a strong genetic component to autism, and one recent study found that autism might trace to an accumulation of many, many gene variants acquired from both mom and dad. Furthermore, families with more than one autistic individual, in particular, not infrequently turn out to be replete with members who show the “broad autism phenotype.” Given the preponderance of genetic involvement in autism, genetics and autism traits in the mother certainly stand as an obvious possibility for what underlies correlation between maternal childhood abuse and autism, far more so than the lingering effects of stress-induced inflammation (stress response is idiosyncratic and could arise from many factors other than abuse) or epigenetics. Not coincidentally, both of the latter are among the sexiest explanations for all things health right now.

Epigenetics carries its own set of problems, articulated quite well in this series of posts. And inflammation and the immune system are becoming the “low vitamin D” of this decade. No matter what the disorder, inflammation and the immune response are the explanatory code words du jour. In one sense, that ubiquity is kind of a “duh”: The immune system isn’t the Lone Ranger of physiology. It engages with and responds to all other body systems, and those other systems all return the favor; no physiological system is an island. So, sure, the immune system and inflammation are probably involved in practically everything. But that doesn’t make them the direct explanation for everything any more than sneezing is what gives you allergies. It’s one result of the allergy, not the cause.

I wonder how the autistic women I know would rate the following experiences in their childhoods. These are the types of non-sexual abuse the authors queried participants about, asking them to assign values from 0 (never) to 4 (very often true): Did the respondent experience any of the following from family members: hitting so hard it left bruises; punishing in a way that seemed cruel; insulting, screaming, and yelling; and punishing with a belt or other hard object? Anecdotally, I know that for many autistic women, the values they’d assign to these would be on the high end. And I know that anyone who grew up where I did in the 1970s, male or female, was a target for this treatment everywhere–at school (even from principals and teachers) and at home. Back then, they called it “discipline” or brushed off bullying as “normal.” Today, it’s (rightfully) called abuse.

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Emily, I would add that the way abuse was tallied in this study probably under-counted a number of experiences that could rightly be called physical or emotional abuse. Physical bullying, coercion and control of many kinds can be abusive without leaving bruises, and is/was probably common in the kinds of body policing (anecdotally) commonly inflicted on autistic or otherwise atypical kids for simply not looking normal. Were those kinds of mistreatment counted as the abuse that they are, I suspect the tabulated “risk” for abused women of having autistic children would be even higher.

I’m wondering if the fact that they were abused would give them a predisposition to seek out mental health professionals and have a more robust network of therapists, psychiatrists etc. They would also be hypersensitive to issues related to behaviors of their children (to make sure their children were not suffering the same fate as they did). Finally, they would not be as likely to shy away from mental health professionals and therefore more likely to seek help and/or a diagnosis for their child.

I tend to look to the sociological factors first when looking for the ‘whys’ as to why a subset of the population would have more or less of an autism rate. Since the past twenty years has seen wildly variability between ethnic groups, states, socio-economic groups etc etc, we almost necessarily have to look to the social factors first, before trying to hunt for genetic or even environmental factors. Am I over-simplifying this issue? Or just thinking more practically?

Well, I’d say it’s a matter of nature vs. nurture here. As you say, Ms. Willingham, some autistics don’t have enough characteristics to meet that threshold definition, and I think that many others, despite being autistic, are able to mask their characteristics to an extent where they appear neurotypical. In either case, individuals will go undiagnosed.

I think that autism first needs to be defined based on a culture. A person may be diagnosed as autistic in one country, but then never meet the threshold definition in another country. For ex. one characteristic of autism in the United States, is that the individual has less eye contact or avoids looks directly at you. Yet in Asian, African, and Latin American cultures, avoiding looking someone in the eyes could be a form of respect.

Also, some cultures and societies believe that corporal punishment is lawful, whether in schools and homes. It would be interesting to see if the rates of autism are higher in these cultures, or whether they are the same when compared to those cultures who do not agree that corporal punishment is lawful.

Interesting idea that I hadn’t seen explored previously! I didn’t get access to this paper, was it regarding abuse while pregnant, or a history of abuse?

Maybe they could give the mothers an ASSQ to see if they have BAP?

Regarding the plausibility of inflammation as a causal mechanism, did you see the maternal CRP study, Elevated maternal C-reactive protein and autism in a national birth cohort (Mol Psychiatry. 2013 Jan 22.)?

It was a big one, 1.2M pregnancies and it showed a rather clear dose relationship between CRP levels during preganacy and resultant risk; i.e., top quintile had a 40% increased risk and top decile had a ~ 80% increased risk relative to botton quartile/decile. Does this give us insight into the possibility of a direct, causal relationship? If there was something *else* that was causing increased risk of both inflammation and autism, it would have to be a hidden artifact affecting wide swaths of the population, and also be able to *coincidentally* alter both parameters in the same way in a dose dependent fashion. I struggle to identify a candidate, but more clever people might have some ideas. (?)

I didn’t get in to read the full paper you refernece here, so I couldn’t see the sources they used to make the persistent inflammation linkage, but I have done some thinking about the PTSD / resultant altered immune phenotype stuff previously; interested parties might look to

Even if the link to autism offspring is spurious toward early life abuse, this is an interesting area from a basic knowledge perspective. The animal models on PTSD/repeated social defeat, and it’s inverse cousin, environmental enrichment tell us that it is possible to persistently modify the neuroimmune and neuro-growth factor environment with bubble up changes to behavior by changes in the physical environment. The immune phenotypes bear similarity to what is seen in humans.

pD … they asked the two questions four years apart, so one was “is your child dx’d with an autism disorder” and four years before (if I recall correctly), it was “what is your history of abuse” with that 0-4 response scale, and including sexual abuse, as well. Yes, it would be very much of interest if they administered a scale to the mothers, looked at history of abuse, and at prevalence of autistic children.

I don’t discount the role of stress in pregnancy outcomes at all, but as I noted, many factors beyond abuse can cause childhood stress, and response to stress is quite individual, so I find this particular tracing from abuse–>stress–>inflammation–>autism very speculative. But I also find myself wary of any explanatory rationale that relies on the latest “hot” scientific motifs.

“Experiences of adversity in the early years of life alter the developing brain. However, evidence documenting this relationship often focuses on severe stressors and relies on peripheral measures of neurobiological functioning during infancy. In the present study, we employed functional MRI during natural sleep to examine associations between a more moderate environmental stressor (nonphysical interparental conflict) and 6- to 12-month-old infants’ neural processing of emotional tone of voice. The primary question was whether interparental conflict experienced by infants is associated with neural responses to emotional tone of voice, particularly very angry speech. Results indicated that maternal report of higher interparental conflict was associated with infants’ greater neural responses to very angry relative to neutral speech across several brain regions implicated in emotion and stress reactivity and regulation (including rostral anterior cingulate cortex, caudate, thalamus, and hypothalamus). These findings suggest that even moderate environmental stress may be associated with brain functioning during infancy. ”

We already have clear evidence on the relationship of stress and physiology …

“In addition, because of some of the key behaviors associated with autism, autistic children are more likely–much more likely [PDF]–than non-autistic children to be abused, physically, emotionally, and sexually.”

For clarification the study, per the statement quoted below in the last paragraph, was limited to a sample of individuals referred into comprehensive community mental services and not indicative of the general population of people on the spectrum.

Sexual and/or physical abuse, as a single factor of risk, predisposes a higher statistical incidence for the need of comprehensive community mental health services with or without an autism spectrum diagnosis or assessment as such.

There is no indication in the study, quoted below, whether or not associated sexual and physical abuse are part of what actually led to a diagnosis among the individuals in the study.

It is unlikely that physical and sexual abuse causes language impairments, deficits in motor skills, but potentially issues with sensory integration problems as chronic stress can lead to issues such as sensitivity to noise, but none of these neuro-developmental impairments is required for a spectrum diagnosis, per the current loose criteria requirements for Asperger’s syndrome and PDDNOS, nor will they be mandatory required for a DSM5 diagnosis.

Ironically, the Gillberg criteria for Asperger’s syndrome provides insurance for the continued capture of some type of neurodevelopmental disorder as language impairments and problems in motor development remain as mandatory criteria.

It is a well known factor that chronic stress can lead to RRBI type behaviors, not only in humans but in other animals, like rats, with the only other requirements currently required for a diagnosis potentially as limited as deficit in ability for back and forth conversation and developing and maintaining peer appropriate friendships. Sexual and physical abuse is among the greatest factors of chronic stress in humans.

In the DSM5 criteria it is identified that symptoms are present in early childhood but may not fully manifest for a diagnosis until social demands exceed social capacity. Physical and sexual abuse certainly rate as a social demand above and beyond what most people deal with in life.

And the symptoms of substance abuse and behavioral addiction per the American Society of Addiction Medicine, ASAM, broad definition of the disease of addiction correlates, to some degree, of what is described in the current loose criteria requirements for PDDNOS or Asperger’s syndrome.

And again, certainly a social stressor that could take one off the broader autism phenotype and on to diagnostic territory per social demands exceeding social capacity.

It is currently very difficult, per DSMIV guidelines, to determine what environmental factors, including physical and sexual abuse and even behavioral addiction, are the social demands that takes one off the broader autism phenotype and on to a spectrum diagnosis for a potential diagnosis of Asperger’s or PDDNOS later in life.

Particularly, when there are no clear neurodevelopmental factors mandatory required for a diagnosis later in life, even with the new DSM5 diagnostic criteria, other than traits than might put one on a broader autism phenotype earlier in life.

I think it is clear that addiction, either substance or behavioral and physical/sexual abuse, alone, does not cause a neuro-developmental disorder.

But, I also think that beyond any potential inflammatory or epigenetic impact, such as what has been described in a recent study of schizophrenia among teenagers who are bullied pulling the switch of epigenetics associated with a maternal infection, there is clearly the potential that the factors of physical/sexual abuse and/or behavioral addiction could be significant factors of social demand that takes one off the broader autism phenotype and onto a diagnosis on the spectrum.

In addition, as far as the prenatal environment per hormonal influences, there is some evidence that sexual, physical or verbal abuse could be factors rising to the level of stress that might alter the hormonal prenatal environment, leading to problems in neurodevelopment.

It is impossible to prevent a broader autism phenotype, even in what is observed as similar traits in the animal kingdom, nor does it appear that would be beneficial, but it is possible to control environmental factors like this that could make the difference between a broader autism phenotype or diagnosed disorder.

I see quite a few people making fun of this study, in various online avenues, but associated research may lead to the real road of determining the increase in actual diagnoses, beyond loose criteria and greater awareness, per recent changes in environmental factors of culture.

There is no evidence that sexual or physical abuse has increased in the last two decades and some evidence that is has decreased, but there is evidence that behavioral addictions are on the rise.

The DSM organization just hasn’t been able to fully wrap their minds around a growing cultural phenomenon yet, to provide appropriate diagnostic criteria to assess and more fully measure the impact.

Some of the ASAM symptoms of behavioral addiction can potentially be defined as an RRBI in clinical practice. And also potentially associated with other problems of social communication to this point, but it does become a lower variable of potential contribution of effect with the more restrictive criteria of the DSM5, and as always less of a potential contributing factor with the Gillberg Criteria that makes a mandatory requirement of criteria for motor development and language impairments.

“Finally, the children in this study sample were referred into comprehensive community mental health services. To our knowledge, no published information is available on how their characteristics may differ from the general population of children with autistic spectrum disorders.”

The strange thing is, if you look at the symptoms of child abuse and the symptoms of autism, they are almost exactly the same so people could just be diagnosing all the kids who have had their parents abuse them as having a mental disorder such as autism. Anyway it would makes sense because abuse in family’s tend to pass on from generation to generation.